Rea on Universalism
Universalism is the thesis that, for any (material) things at any time, there is something they compose at that time. In McGrath (1998), I argued that, contrary Peter van Inwagen (1990), Universalism is compatible with common sense metaphysical facts such as these: that I am now composed of atoms, that I was ten years ago composed of different atoms, but that the atoms that composed me ten years ago still exist today. However, I insisted that the price of this union is the admission of pluralism about composition, i.e., the thesis that some composition is automatic while some is not. Such pluralism, when conjoined with Universalism and common sense metaphysics, entails the possibility, indeed the actuality, of co-location.Michael Rea (1999) agrees that Universalism is compatible with common sense metaphysics but denies that the Universalist needs to pay the price of co-location. Rea concludes that Universalists who deny co-location may reject the principle (P1), used in my argument: (P1)For any xs, if the xs automatically compose something at t, there is exactly one object they automatically compose at t, their sum. Rea, in effect, denies that 'automatically composing something' entails 'there being something automatically composed'. In this note, I will describe some of the problems that Universalists face by giving up (P1) and pursuing Rea's strategy instead.